This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Our laboratory uses macromolecular crystallography to study the structure and function of proteins and enzymes of interest. These proteins include RebC, an enzyme involved in the biosynthesis of a natural product know to have antitumor activity;PflAE, a Radical SAM enzyme;and MeaB, a medicinally relevant GTPase. The structures of these enzymes have all been solved very recently in our lab (all manuscripts in preparation and unpublished results), and require important follow-up experiments.